ISR Performance Rear Diff Mount Support Brace - Scion FR-S / Subaru BRZ 13+

The ISR Performance Rear Diff Mount Support Brace is a chassis brace that reinforces the rear differential mounting on the Scion FR-S, Subaru BRZ, and Toyota 86 (ZN6/ZC6 platform). It addresses a known weak point in the chassis: under hard launches, sustained drift duty, or any aggressive rear-end load, the factory diff mount flexes and shifts. This brace ties the diff mount to the surrounding chassis structure for noticeably tighter rear-end response and longer mount life.

What It Does

The factory rear differential on the FR-S/BRZ/86 mounts to the body through a relatively flexible bracket arrangement. That flex shows up as drivetrain wind-up on launches, vague rear-end feel under power, and accelerated wear on the diff bushings. The ISR support brace ties the diff mount to additional chassis structure, dramatically reducing that movement. A common upgrade on FR-S/BRZ/86 builds running upgraded power, sticky tires, or any kind of drift duty.

Fitment

• 2013-2016 Scion FR-S
• 2013-2020 Subaru BRZ (first-gen ZC6)
• 2017-2019 Toyota 86 (ZN6)

What's in the Box

• 1x Rear differential mount support brace
• 1x Hardware pack

Product Details

Brand: ISR Performance

Part Number: IS-RDMS-FRS

Type: Rear Differential Mount Support Brace

Vehicle Fitment: 2013-2016 Scion FR-S, 2013-2020 Subaru BRZ, 2017-2019 Toyota 86

Application: Reduces rear diff mount flex on launches and under power

Installation: Bolt-on, hardware included

Sold: Individually (one brace per vehicle)

Legality: Off-road and competition use only